Battery pack and manufacturing method for the same

ABSTRACT

A battery pack having a case where connection tabs can be accurately positioned within the case and where welding holes in the case are formed to provide access to a welding rod and to allow heat to escape. Connection tabs are fixed into a lower case, batteries are arranged in the case, and then a welding process is performed to attach electrode tabs of the battery to the connection tabs so that the batteries can be connected together, to an external terminal and to a protection circuit module.

CLAIM OF PRIORITY

This application makes reference to, incorporates the same herein, andclaims all benefits accruing under 35 U.S.C. §119 from an applicationfor BATTERY PACK AND MANUFACTURING METHOD FOR THE SAME earlier filed inthe Korean Intellectual Property Office on 16 Aug. 2011 and there dulyassigned Korean Patent Application No. 10-2011-0081180.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate to a battery pack and amanufacturing method for the same.

2. Description of the Related Art

A battery pack having a plurality of batteries electrically connectedcan be used as a power storage device that enables power stored in thebatteries to be used whenever necessary.

The battery pack may include a temperature sensor for monitoringtemperature information of batteries and preventing accidents such asfire or explosion by finding a probable emergency such as overheating,and a circuit for processing output signals of the temperature sensor.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a battery pack in whichelectrode tabs of a battery mounted within a lower case and connectiontabs are welded together.

Embodiments of the present invention also provide a manufacturing methodfor the battery pack, which can be simplified by welding electrode tabsto connection tabs at the same time through bonding part holes formed ina lower case of the battery back, and which can prevent welding failuresby fixing the connection tabs at accurate positions using a connectiontab mounting portion and a rib in the lower case.

According to one aspect of the present invention, there is provided abattery pack that includes a plurality of batteries, each including afirst electrode tab and a second electrode tab, a plurality ofconnection tabs electrically connected to the plurality of batteries, aprotection circuit module electrically connected to the plurality ofbatteries and to the connection tabs, a lower case accommodating thebatteries, the connection tabs and the protection circuit module, thelower case includes a plurality of bonding part holes arranged atlocations where the first electrode tabs and the second electrode tabsof the batteries are connected to the connection tabs and an upper casecovering a top portion of the lower case.

The bonding part holes may include a plurality of first bonding partholes arranged at locations corresponding to where the first electrodetabs are connected to the connection tabs and a plurality of secondbonding part holes arranged at locations corresponding to where thesecond electrode tabs are connected to the connection tabs, wherein eachof the first bonding part holes being wider than each of the secondbonding part holes. Each of the connection tabs may include a connectionpart having an interconnection, an insulating layer surrounding theinterconnection and a bonding part electrically connected to one of thefirst electrode tab and the second electrode tab, the bonding parthaving the insulating layer removed therefrom.

Each bonding part may include a first bonding part connected to one ofthe first electrode tabs and a second bonding part connected to one ofthe second electrode tabs, wherein each first bonding part is wider thaneach second bonding part. The connection part may include a fixing holeto fix to the lower case. The connection part may include a fixing holeto attach to a rib protruding from an inside side of the lower case, therib may pass through the fixing hole. The bonding part holes may emitheat from the bonding parts. The bonding parts may include one of nickelor a nickel alloy. One surface of each of the bonding parts may beconnected to one of the first electrode tab and the second electrodetab, and a surface opposite from the one surface of each of the bondingparts may be exposed to an outside of the lower case through acorresponding one of the bonding part holes. The connection tabs may bemounted in connection tab mounting parts that may be recesses arrangedon an inside of the lower case. The lower case may include a labelattached to an outside thereof that may cover the bonding part holes.

According to another aspect of the present invention, there is provideda method of manufacturing a battery pack, including preparing a lowercase perforated by a plurality of bonding part holes, mounting aplurality of connection tabs into the lower case, the connection tabsincluding a plurality of bonding parts arranged at locations thatcorrespond to the bonding part holes, mounting a plurality of batteriesinto the lower case, each of the batteries including a first electrodetab and a second electrode tab that are arranged to correspond to thebonding parts, welding the first electrode tabs and the second electrodetabs to corresponding ones of the bonding parts after the batteries havebeen mounted in the lower case and attaching an upper case to the lowercase after the welding.

The mounting of the connection tabs may include fixing the connectiontabs to the lower case by inserting ribs protruding from an inside sideof the lower case into fixing holes arranged in the connection tabs. Thewelding may include welding the first and second electrode tabs to thebonding parts while the batteries are mounted in the lower case andarranged within a jig. The welding may include spot welding the firstand second electrode tabs to the bonding parts. The welding may includepositioning a first welding rod below one of the bonding parts exposedthrough one of the bonding part holes and positioning a second weldingrod on one of the first and second first electrode tabs at a locationdirectly above the first welding rod. The preparing of the lower casemay include preparing the lower case such that the bonding part holesinclude first bonding part holes that are larger than second bondingpart holes, the first bonding part holes may correspond to the firstelectrode tabs and the second bonding part holes may correspond to thesecond electrode tabs. The method may also include attaching a label toan outside of the lower case to cover the bonding part holes.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the attendantadvantages thereof, will be readily apparent as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings in which likereference symbols indicate the same or similar components, wherein:

FIG. 1 is a perspective view of a battery pack according to anembodiment of the present invention;

FIG. 2 is a perspective view of the battery pack of FIG. 1, from whichan upper case is removed;

FIG. 3 is vertically sectional view taken along the line A-A′ of FIG. 2;

FIG. 4 is an enlarged sectional view of a ‘B’ portion of FIG. 3;

FIG. 5A is a plan view of a lower case of FIG. 2, FIG. 5B is a plan viewillustrating a state in which connection tabs are mounted in a lowercase of FIG. 5A, FIG. 5C is a plan view illustrating a state in whichbatteries are mounted in the lower case of FIG. 5B, and FIG. 5D is asectional view taken along the line A-A′ of FIG. 3; and

FIG. 6 is a plan view illustrating a rear surface of the lower caseshown in FIG. 5A.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the present embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings such that they can easily be made and used by those skilled inthe art.

First, the battery pack 1000 according to the embodiment of the presentinvention will be described.

FIG. 1 is a perspective view of a battery pack according to anembodiment of the present invention, FIG. 2 is a perspective view of thebattery pack of FIG. 1, from which an upper case is removed, FIG. 3 isvertically sectional view taken along the line A-A′ of FIG. 2, FIG. 4 isan enlarged sectional view of a ‘B’ portion of FIG. 3, and FIG. 6 is aplan view illustrating a rear surface of the lower case shown in FIG.5A.

The battery pack 1000 may include a plurality of batteries 1100,connection tabs 1200, 1300, 1400 and 1500, a protection circuit module1600 and a case 1700. The battery pack 1000 may further include a label1800.

In the battery pack 1000, the plurality of batteries 1100 areelectrically connected using one or more connection tabs 1200. Inaddition, the connection tabs 1200 are electrically connected to theprotection circuit module 1600. In detail, the batteries 1100 areelectrically connected to the protection circuit module 1600 through theconnection tabs 1200. The batteries 1100 have electrode tabs havingdifferent polarities welded to a bonding part 1220 of the connection tab1200. The battery pack 1000 has bonding part holes 1725 and 1726 formedin the lower case 1720. The bonding part holes 1725 and 1726 are formedto allow the connection tab 1200 and the batteries 1100 to be welded ina jig at the same time after the connection tab 1200 and the batteries1100 are mounted in the lower case 1720.

The batteries 1100 may be connected in series or parallel to each other.The batteries 1100 may be connected in a combination of series andparallel connections such that some of the plurality of batteries 1100are connected in parallel to each other and the other of the pluralityof batteries 1100 are connected in series each other. In the illustratedembodiment, 4 batteries 1110, 1120, 1130 and 1140 are shown, but theinvention is not limited thereto. In the battery pack 1000 according tothe embodiment of the present invention, a predetermined number ofbatteries may be arranged horizontally or vertically, but the number ofbatteries is not limited thereto. The batteries may be arranged invarious manners in view of the number.

In addition, the following description will be made with regard to afirst battery 1110 of the plurality of batteries 1100 by way of example.The first battery 1110 may be implemented by a pouch type rechargeablebattery, but not limited thereto. The first battery 1110 may havevarious shapes.

The first battery 1110 includes a first electrode tab 1111, a secondelectrode tab 1112 and an insulation part 1113. The first electrode tab1111 may be a positive electrode tab and the second electrode tab 1112may be a negative electrode tab. In addition, it is assumed that sidesurfaces of the first battery 1110 are wrapped by a label made of aninsulating material.

The first battery 1110 may be implemented as a lithium-ion battery, butis not limited thereto. The first battery 1110 may instead beimplemented as a nickel-cadmium battery, a nickel metal hydride (NiMH)battery, and so on.

In the battery pack 1000, one or more connection tabs 1200, 1300, 1400and 1500 are used to electrically connect the plurality of batteries1100 to each other. The connection tabs 1200, 1300, 1400 and 1500 may beimplemented in various manners according to the arrangement of thebatteries 1100. However, shapes of the connection tabs 1200, 1300, 1400and 1500 are not limited to the illustrated shapes. The connection tabs1200, 1300 and 1500 include connection leads 1250, 1350 and 1550 to beelectrically connected to the protection circuit module 1600. However,positions of the connection tabs 1200, 1300 and 1500 having theconnection leads 1250, 1350 and 1550 are limited to those illustrated inthe embodiment. In addition, bonding parts 1220, 1320, 1330, 1340, 1420,1430, 1440, and 1520 formed in the connection tabs 1200, 1300, 1400 and1500 may include positive electrode bonding parts 1320, 1420, 1440, and1520 connected to positive electrode tabs of batteries, and negativeelectrode bonding parts 1220, 1330, 1340, and 1430 connected to negativeelectrode tabs of batteries. The bonding parts 1220, 1320, 1330, 1340,1420, 1430, 1440, and 1520 may be implemented in various mannersaccording to positions of batteries connected thereto and polarities ofbattery tabs.

First, the first connection tab 1200 connecting the first battery 1110and the circuit board 1610 will now be described.

The first connection tab 1200 includes a first connection part 1210, afirst bonding part 1220, a fixing hole 1211, and a connection lead 1250.

The first connection part 1210 includes an insulating layer 1212surrounding an interconnection 1211 and the outside of theinterconnection 1211. The first connection part 1210 has a fixing hole1211 to allow a rib 1724 of the lower case 1720 to be tightly fixedthereto, which will later be described. As the fixing hole 1211 and therib 1724 are engaged with each other, the first connection tab 1200 canbe fixed at an accurate position. In addition, the first connection tab1200 may have a connection tab mounting part 1727 formed in a case plate1721 to later be described. The connection tab mounting part 1727 hasthe same shape as the first connection tab 1200 and is recessed to allowthe first connection tab 1200 to be mounted therein. The firstconnection part 1210 is positioned in the connection tab mounting part1727 to then be stably fixed.

The first bonding part 1220 is formed at a portion of the firstconnection part 1210. The first bonding part 1220 is electricallyconnected to the interconnection 1213 and is shaped of a plate made outof a metal. The insulating layer is removed from the plate of the firstbonding part 1220. The metal may include nickel or a nickel alloy. Inaddition, the second electrode tab 1112 of the first battery 1110 ismounted on a top portion of the first bonding part 1220, so that awelding part (G) is welded to the first bonding part 1220 to then beelectrically connected thereto.

In addition, the first bonding part 1220 is spot-welded to the secondelectrode tab 1112 in a state in which it is mounted within the lowercase 1720. In the welding, a pair of upper and lower welding rods 2100and 2200 to be described later are used. The upper welding rods 2100 arepositioned on the second electrode tab 1112, and the lower welding rods2200 are positioned beneath the first bonding part 1220. The firstbonding part 1220 may be exposed through the bonding part holes 1726 inthe lower case 1720, to be described later, such that the bottom surfaceof the first bonding part 1220 corresponds to the lower welding rod2200. The pair of welding rods 2100 and 2200 are used to weld the firstbonding part 1220 and the second electrode tab 1112 at the same time.

The second connection tab 1300 includes a second connection part 1310, asecond bonding part 1320, a third bonding part 1330, a fourth bondingpart 1340 and a fixing hole 1311. The second connection tab 1300electrically connects the first battery 1110, the second battery 1120and the fourth battery 1140 to each other. In addition, the secondconnection tab 1300 may further include a connection lead 1350 to beelectrically connected to protection circuit module 1600.

The second connection tab 1300 is substantially the same as the firstconnection tab 1200 in view of configuration and function, except forconfigurations of second to fourth bonding parts 1320, 1330 and 1340.Accordingly, the components that have the same function as those of thedrawings of the first connection tab 1200 are referred to as the samereference numerals, and the following description will focus onconnections of the second to fourth bonding parts 1320, 1330 and 1340.

The second bonding part 1320 is connected to the first electrode tab1111 of the first battery 1110 after the first electrode tab 1111 isplaced thereon. The third bonding part 1330 is connected to the secondelectrode tab 1122 of the second battery 1120 after the second electrodetab 1122 is placed thereon. In addition, the fourth bonding part 1340 isconnected to the second electrode tab 1142 of the fourth battery 1140after the second electrode tab 1142 is placed thereon. The secondconnection tab 1300 has an interconnection formed in the secondconnection part 1310 to allow the batteries to be connected in series orparallel to each other. In addition, the second connection tab 1300 isplaced in the connection tab mounting part 1727 of the case plate 1721and stably fixed by the rib 1724 penetrating through the fixing hole1311.

The third connection tab 1400 includes a third connection part 1410, afifth bonding part 1420, a sixth bonding part 1430, a seventh bondingpart 1440 and a fixing hole 1411. The third connection tab 1400 issubstantially the same as the second connection tab 1300 in view ofconfiguration and function, except for configurations of fifth toseventh bonding parts 1420, 1430 and 1440. Accordingly, the componentsthat have the same function as those of the drawings of the secondconnection tab 1300 are referred to as the same reference numerals, andthe following description will focus on connections of the fifth toseventh bonding parts 1420, 1430 and 1440.

The fifth bonding part 1420 is connected to the first electrode tab 1121of the second battery 1120 after the first electrode tab 1121 is placedthereon. The sixth bonding part 1430 is connected to the secondelectrode tab 1132 of the third battery 1130 after the second electrodetab 1132 is placed thereon. In addition, the seventh bonding part 1440is connected to the first electrode tab 1141 of the fourth battery 1140after the second electrode tab 1142 is placed thereon. The thirdconnection tab 1400 has an interconnection formed in the thirdconnection part 1410 to allow the batteries to be connected in series orparallel to each other. In addition, the third connection tab 1400 isplaced in the connection tab mounting part 1727 of the case plate 1721and stably fixed by the rib 1724 penetrating through the fixing hole1411.

The fourth connection tab 1500 includes a fourth connection part 1510,an eighth bonding part 1520, a fixing hole 1511 and a connection lead1550. The fourth connection tab 1500 is substantially the same with thefirst connection tab 1200 in view of configuration and function, exceptfor the configuration of the eighth bonding part 1520. Accordingly, thecomponents that have the same function as those of the drawings of thefirst connection tab 1200 are referred to as the same referencenumerals, and the following description will focus on connectionmechanism of the eighth bonding part 1520.

The eighth bonding part 1520 is connected to the first electrode tab1131 of the third battery 1130 after the first electrode tab 1131 isplaced thereon. When the plurality of batteries 1110, 1120, 1130 and1140 are connected in series, as shown, the first electrode tab 1131 ofthe third battery 1130 may be a highest-potential electrode and may beelectrically connected to the protection circuit module 1600 using aconnection lead 1550 of the fourth connection tab 1500. In addition,when the plurality of batteries 1110, 1120, 1130 and 1140 are connectedin series, as shown, the second electrode tab 1112 of the first battery1110 may be a lowest-potential electrode and may be electricallyconnected to the protection circuit module 1600 using a connection lead1250 of the first connection tab 1200.

The protection circuit module 1600 includes a circuit board 1610, aconnection tab fixing part 1620 and an external terminal 1630.

The circuit board 1610 may include an electric device (not shown) and acircuit pattern layer (not shown). The electric device collects stateinformation such as charging status or temperature of the battery 1100and controls charging/discharging operations of the battery 1100. Inaddition, the circuit board 1610 has a connection tab fixing part 1620to which the connection tab electrically connected to the battery 1100is fixed. The connection tab fixing part 1620 is formed as athrough-hole through which the lead formed at one side of the connectiontab penetrates and is then fixed by soldering. The external terminal1630 may be used to perform data communication with an external circuit(not shown) or to supply power to an external power supply (not shown)or an external load (not shown).

The case 1700 includes an upper case 1710 and a lower case 1720.

In the case 1700, the batteries 1100, the connection tabs 1200, 1300,1400 and 1500, and the protection circuit module 1600 are accommodatedin the lower case 1720, and the upper case 1710 covers a top portion ofthe lower case 1720.

The lower case 1720 has a case sidewall 1722 vertically extending at anend of the case plate 1721, forming an internal space. In addition, thelower case 1720 may have a label 1800 attached to the outside of thecase 1700 so as to cover the bonding part holes 1725 and 1726.

The case plate 1721 includes a partition wall 1723, a rib 1724, bondingpart holes 1725 and 1726 and a connection tab mounting part 1727.

The partition wall 1723 may suppress movement of the batteries 1100accommodated in the lower case 1720 and may allow the respectivebatteries 1100 to be placed at accurate positions.

The rib 1724 may be formed as a protrusion. The rib 1724 may include aplurality of ribs formed at regions of the case plate 1721 where theconnection tabs 1200, 1300, 1400 and 1500 are placed. The ribs 1724allow the connection tabs 1200, 1300, 1400 and 1500 to be fixed ataccurate positions.

The bonding part holes 1725 and 1726 may be formed as through-holes atpositions corresponding to bonding parts 1220, 1320, 1330, 1340, 1420,1430, 1440, and 1520 of the connection tabs 1200, 1300, 1400 and 1500.

The bonding part holes 1725 and 1726 may expose one side surfaces of thefirst electrode bonding part 1320, 1420, 1440, 1520 and the secondelectrode bonding part 1220, 1330, 1340, 1430. In addition, the bondingpart holes 1725 and 1726 may be passages through which heat of the firstelectrode bonding part 1320, 1420, 1440, 1520 and the second electrodebonding part 1220, 1330, 1340, 1430.

The first bonding part hole 1725 may be wider than the second bondingpart hole 1726. That is to say, an area (B×C) of the first bonding parthole 1725 may be larger than an area (D×E) of the second bonding parthole 1726. In this case, it is assumed that the first bonding part hole1725 allows the first electrode bonding part 1320, 1420, 1440, 1520 tobe connected to positive or first electrodes of the batteries 1100.Referring to FIG. 6, in the lower case 1720, the bonding part holes 1725and 1726 may have the same shapes as the bonding parts 1220, 1320, 1330,1340, 1420, 1430, 1440, and 1520. The bonding part holes 1725 and 1726and the bonding parts 1220, 1320, 1330, 1340, 1420, 1430, 1440, and 1520may have various shapes, including a rectangular shape or a circularshape.

The connection tab mounting part 1727 may be recessed to have a regionbetween the batteries 1100 and the case plate 1721 to allow theconnection tabs 1200, 1300, 1400 and 1500 to be mounted therein. Theconnection tab mounting part 1727 may be recessed by a thicknesscorresponding to a thickness of each of the connection tabs 1200, 1300,1400 and 1500. The connection tab mounting part 1727 allows theconnection tabs 1200, 1300, 1400 and 1500 to be mounted at accuratepositions and be stably fixed such that the connection tabs 1200, 1300,1400 and 1500 are mounted in regions recessed from the case plate 1721.In addition, the connection tab mounting part 1727 has the ribs 1724 ata path along which the connection tabs 1200, 1300, 1400 and 1500 aremounted. The ribs 1724 are inserted into fixing holes 1211, 1311, 1411and 1511 of the connection tabs 1200, 1300, 1400 and 1500, therebyfixing the connection tabs 1200, 1300, 1400 and 1500.

The label 1800 may be attached to the outside of the case 1700 so as tocover the bonding part holes 1725 and 1726. The label 1800 may beattached to the entire surface of the lower case 1720 or portions 1810and 1820 corresponding to the bonding part holes 1725 and 1726.

A manufacturing method for a battery pack 1000 will now be described.

FIG. 5A is a plan view of a lower case of FIG. 2, FIG. 5B is a plan viewillustrating a state in which connection tabs are mounted in a lowercase of FIG. 5A, FIG. 5C is a plan view illustrating a state in whichbatteries are mounted in the lower case of FIG. 5B, and FIG. 5D is asectional view taken along the line A-A′ of FIG. 3.

The manufacturing method for a battery pack 1000 includes preparing thelower case 1720, mounting the connection tabs 1200, 1300, 1400 and 1500,mounting batteries and completing the battery pack 1000.

Referring to FIG. 5A, in the preparing of the lower case 1720, the lowercase 1720 having the bonding part holes 1725 and 1726 is prepared. Inthe lower case 1720, an area of the bonding part hole 1725 formed at thebonding part connected to a first electrode tab of battery may be largerthan that of the bonding part hole 1726 formed at the bonding partconnected to a second electrode tab. The lower case 1720 has the casesidewall 1722 vertically extending at an end of the case plate 1721,forming the internal space. The connection tabs 1200, 1300, 1400 and1500 and batteries 1100 may be accommodated within the internal space.

Referring to FIG. 5B, in the mounting of the connection tabs 1200, 1300,1400 and 1500, the connection tabs 1200, 1300, 1400 and 1500 are mountedsuch that the bonding parts 1220, 1320, 1330, 1340, 1420, 1430, 1440,and 1520 are positioned to correspond to the bonding part holes 1725 and1726 of the lower case 1720. The connection tabs 1200, 1300, 1400 and1500 are electrically connected using the protection circuit board 1610and connection leads. The connection parts 1210, 1310, 1410 and 1510 ofthe connection tabs 1200, 1300, 1400 and 1500 can be stably fixed ataccurate positions such that the ribs 1724 are inserted into the fixingholes 1211, 1311, 1411 and 1511. The bonding part holes 1725 and 1726may expose one side surfaces of the electrode bonding parts 1220, 1320,1330, 1340, 1420, 1430, 1440, and 1520.

Referring to FIG. 5C, in the mounting of the batteries 1100, thebatteries 1100 are mounted in the lower case 1720 such that first andsecond electrode tabs of the batteries 1100 are positioned on topsurfaces of the bonding parts 1220, 1320, 1330, 1340, 1420, 1430, 1440,and 1520.

Referring to FIG. 5D, in the welding, after the bonding parts 1220,1320, 1330, 1340, 1420, 1430, 1440, and 1520 and the battery electrodetabs are mounted in the lower case 1720, the bonding parts 1220, 1320,1330, 1340, 1420, 1430, 1440, and 1520 and the battery electrode tabsare welded together. The welding is performed by disposing the lowercase 1720 having the connection tabs 1200, 1300, 1400 and 1500 and thebatteries 1100 accommodated therein in a jig. In the welding, firstwelding rods 2100 are disposed over on the lower case 1720, and secondwelding rods 2200 are disposed under the bonding parts 1220, 1320, 1330,1340, 1420, 1430, 1440, and 1520 exposed to the outside through thebonding part holes 1725 and 1726. The welding may include spot welding.In the mounting of the connection tabs 1200, 1300, 1400 and 1500 and themounting of the batteries 1100, the connection tabs 1200, 1300, 1400 and1500 and the batteries 1100 are stably mounted at accurate positions inthe lower case 1720, thereby preventing welding failures of the batterypack.

In addition, the bonding part holes 1725 and 1726 are formed in thelower case 1720, and the connection tabs 1200, 1300, 1400 and 1500 andthe batteries 1100 are mounted in the lower case 1720, the connectiontabs 1200, 1300, 1400 and 1500 and the batteries 1100 are weldedaltogether, thereby simplifying the manufacturing process. Further,since the connection tabs 1200, 1300, 1400 and 1500 are fixed ataccurate positions in the lower case 1720, it is possible to preventwelding failures due to movement of the bonding parts 1220, 1320, 1330,1340, 1420, 1430, 1440, and 1520 and the first and second connectiontabs during welding.

The completing of the battery pack 1000 comprises manufacturing thebattery pack 1000 by covering a top portion of the lower case 1720 bythe upper case 1710. In addition, the completing of the battery pack1000 comprises attaching a label 1800 to cover the bonding part holes1725 and 1726.

Exemplary embodiments of a battery pack a manufacturing method for thesame have been disclosed herein, and although specific terms areemployed, they are used and are to be interpreted in a generic anddescriptive sense only and not for purpose of limitation. Accordingly,it will be understood by those of ordinary skill in the art that variouschanges in form and details may be made without departing from thespirit and scope of the present invention as set forth in the followingclaims.

What is claimed is:
 1. A battery pack, comprising: a plurality ofbatteries, each including a first electrode tab and a second electrodetab; a plurality of connection tabs electrically connected to theplurality of batteries; a protection circuit module electricallyconnected to the plurality of batteries and to the connection tabs; alower case accommodating the batteries, the connection tabs and theprotection circuit module; and an upper case covering a top portion ofthe lower case, wherein the lower case includes a plurality of bondingpart holes arranged at locations where the first electrode tabs and thesecond electrode tabs of the batteries are connected to the connectiontabs, wherein the lower case includes a label attached to an outsidethereof that covers the bonding part holes.
 2. The battery pack of claim1, wherein the bonding part holes comprises: a plurality of firstbonding part holes arranged at locations corresponding to where thefirst electrode tabs are connected to the connection tabs; and aplurality of second bonding part holes arranged at locationscorresponding to where the second electrode tabs are connected to theconnection tabs, wherein each of the first bonding part holes beingwider than each of the second bonding part holes.
 3. The battery pack ofclaim 1, wherein each of the connection tabs comprises a fixing hole tofix to the lower case.
 4. The battery pack of claim 1, wherein each ofthe connection tabs comprises a fixing hole to attach to a ribprotruding from an inside side of the lower case, the rib passingthrough the fixing hole.
 5. The battery pack of claim 1, wherein thelower case further comprises a plurality of connection tab mountingparts, the connection tab mounting parts being recesses arranged on aninside of the lower case, wherein the connection tabs are arrangedwithin the connection tab mounting parts.
 6. The battery pack of claim1, wherein ones of the connection tabs extend from one of the first andsecond electrode tabs of one of the batteries to one of the first andsecond electrode tabs of another of the batteries, and without extendingexternal to a combination of the upper case coupled to the lower case.7. The battery pack of claim 1, wherein the first electrode tab is apositive electrode tab and the second electrode tab is a negativeelectrode tab.
 8. The battery pack of claim 1, wherein the firstelectrode tab has an opposite polarity than the second electrode tab foreach of the plurality of batteries.
 9. The battery pack of claim 1,wherein each of the connection tabs comprises: a connection part havingan interconnection; an insulating layer surrounding the interconnection;and a bonding part electrically connected to one of the first electrodetab and the second electrode tab, the bonding part having the insulatinglayer removed therefrom.
 10. The battery pack of claim 9, wherein eachbonding part comprises: a first bonding part connected to one of thefirst electrode tabs; and a second bonding part connected to one of thesecond electrode tabs, wherein each first bonding part is wider thaneach second bonding part.
 11. The battery pack of claim 9, wherein theconnection tabs do not extend external to a combination of the upper andthe lower cases.
 12. The battery pack of claim 9, wherein the bondingparts are comprised of a material selected from a group consisting ofnickel and a nickel alloy.
 13. The battery pack of claim 9, wherein onesurface of each of the bonding parts is connected to one of the firstelectrode tab and the second electrode tab, and a surface opposite fromthe one surface of each of the bonding parts is exposed to an outside ofthe lower case through a corresponding one of the bonding part holes.14. A manufacturing method for a battery pack, comprising: preparing alower case perforated by a plurality of bonding part holes; mounting aplurality of connection tabs into the lower case, the connection tabsincluding a plurality of bonding parts arranged at locations thatcorrespond to the bonding part holes; mounting a plurality of batteriesinto the lower case, each of the batteries including a first electrodetab and a second electrode tab that are arranged to correspond to thebonding parts; welding the first electrode tabs and the second electrodetabs to corresponding ones of the bonding parts after the batteries havebeen mounted in the lower case; and attaching an upper case to the lowercase after the welding.
 15. The manufacturing method of claim 14,wherein the mounting of the connection tabs comprises fixing theconnection tabs to the lower case by inserting ribs protruding from aninside side of the lower case into fixing holes arranged in theconnection tabs.
 16. The manufacturing method of claim 14, wherein thewelding comprises welding the first and second electrode tabs to thebonding parts while the batteries are mounted in the lower case andarranged within a jig.
 17. The manufacturing method of claim 16, whereinthe welding comprises spot welding the first and second electrode tabsto the bonding parts.
 18. The manufacturing method of claim 16, whereinthe welding comprises positioning a first welding rod below one of thebonding parts exposed through one of the bonding part holes andpositioning a second welding rod on one of the first and second firstelectrode tabs at a location directly above the first welding rod. 19.The manufacturing method of claim 14, wherein the bonding part holescomprise first bonding part holes that are larger than second bondingpart holes, the first bonding part holes corresponding to the firstelectrode tabs and the second bonding part holes corresponding to thesecond electrode tabs.
 20. The manufacturing method of claim 14, furthercomprising attaching a label to an outside of the lower case to coverthe bonding part holes.